<% # Be sure you have a JS array called "languages" where the index is the artwork description id and the value is the text you want to appear %>
<select id="description_select">
  <%= options_from_collection_for_select(description_select, value_method, text_method, selected) %>
</select>
<%= observe_field :description_select, :function => %Q{$('#{update}').update(languages[value])} %>